VOOZH about

URL: https://oeis.org/A177601

⇱ A177601 - OEIS

login
A177601
Number of permutations of 3 copies of 1..n avoiding adjacent step pattern up, down, down, up.
0
1, 20, 1477, 263978, 93489715, 57920130894, 57577729726875, 86198179666698834, 185132216218421052414, 548986840452318863546904
OFFSET
1,2
CROSSREFS
Sequence in context: A127847 A363512 A193309 * A200900 A177603 A160308
KEYWORD
nonn
AUTHOR
R. H. Hardin, May 10 2010
EXTENSIONS
a(9)-a(10) from Alois P. Heinz, Nov 02 2013
STATUS
approved